Opium poppy (Papaver somniferum L.) is one of the most ancient medicinal plants of the world. Its medicinal and economic importance is highly dependent on the benzylisoquinoline alkaloid (BIA) production. The plant remains the only commercial source for the narcotic analgesics: morphine and codeine. In addition to its medicinal use, opium poppy is rich in oil content in seeds which makes it a valuable source of food. Opium poppy has served as a model organism to study biosynthesis of benzylisoquinoline alkaloids in plants. Recently, the emergence of omics tools including genomics, transcriptomics, proteomics, and metabolomics, together with the applications of functional genomics, has accelerated the discovery of genes involved in BIA biosynthesis in opium poppy. In this chapter, recent studies involving different omics approaches have been presented to understand the biosynthesis and regulation of BIA metabolism in opium poppy. The applications of multi-omics approaches and their integration for the discovery of new genes have been reviewed. Finally, metabolic engineering studies on opium poppy have been discussed. © Springer Nature Switzerland AG 2021.